Swelling resistance of advanced austenitic alloy A709 and its comparison with 316 stainless steel at high damage levels
Swelling resistance of advanced austenitic alloy A709 and its comparison with 316 stainless steel at high damage levels
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DOI：
10.1016/j.jnucmat.2019.151818
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发表时间：
2019-12-15
影响因子：
3.1
通讯作者：
Shao, Lin
中科院分区：
文献类型：
--
作者：
Kim, Hyosim;Gigax, Jonathan G.;Shao, Lin
A709合金是一种奥氏体合金，开发用于热电厂的动力锅炉应用，并被认为是第四代反应堆和聚变反应堆的候选结构材料，特别是基于其比316型不锈钢更高的蠕变强度。然而，改进的热蠕变性能不一定意味着改进的耐辐射性，特别是关于空隙膨胀。由于目前没有关于A709高通量的中子辐照数据，因此在本研究中，在相同条件下使用3.5 MeV Fe+2离子辐照A709和冷加工的316，以100和400峰dpa之间的剂量进行辐照。316的溶胀行为对于中子和离子辐照都是众所周知的，因此A709和316在离子辐照下的相对溶胀行为可以提供A709在中子辐照环境中的溶胀行为的指示。在500-600 ℃的范围内观察到A709在离子辐照下的溶胀，在575 ℃达到峰值。A709和316最终在575 ℃下的离子辐照下以类似于1%/dpa的速率溶胀，这与在中子辐照期间观察到的316的溶胀一致。但是，在任何给定的dpa速率下，A709具有比316显著更长的瞬态状态，这表明在自离子辐照下A709比316具有增强的抗溶胀性。A709和316在400峰dpa时达到的溶胀水平分别为55%和90%。在时间和空间上调整分配的局部dpa水平，在每个剂量的溶胀诱导的离子范围的增加和伴随的密度降低。还观察到在每种合金中的瞬态状态的持续时间随着局部dpa速率的增加而增加，但是具有不同的通量灵敏度，推测这是由两种合金的非常不同的组成引起的。(C)2019爱思唯尔B. V.保留所有权利。
Alloy A709 is an austenitic alloy developed for power boiler applications in thermal power plants and is being considered as a candidate structural material for Generation IV reactors and fusion reactors, based especially on its increased creep strength over Type 316 stainless steel. However, improved thermal creep properties would not necessarily imply improved radiation resistance, especially with respect to void swelling. Since there are currently no neutron irradiation data on A709 to high fluences, A709 and cold-worked 316 were irradiated in the present study under identical conditions to doses between 100 and 400 peak dpa using irradiation by 3.5 MeV Fe+2 ions. The swelling behavior of 316 is well-known for both neutron and ion irradiation, thus the relative swelling behavior of A709 and 316 under ion irradiation might provide an indication of the swelling behavior of A709 in a neutron irradiation environment. Swelling of A709 under ion irradiation was observed over the range of 500-600 degrees C, peaking at 575 degrees C. Both A709 and 316 eventually swelled at a rate of similar to 1%/dpa under ion irradiation at 575 degrees C, consistent with the swelling of 316 observed during neutron irradiation. But A709 had a significantly longer transient regime than 316 at any given dpa rate, demonstrating enhanced swelling resistance of A709 over 316 under self-ion irradiation. The swelling levels reached at 400 peak dpa were 55% and 90% for A709 and 316, respectively. The assigned local dpa levels were adjusted both temporally and spatially at each dose for swelling-induced increases in the ion range and concomitant decreases in density. The duration of the transient regime in each alloy was also observed to increase as the local dpa rate increased, but with a different flux sensitivity that is speculated to arise from the very different composition of the two alloys. (C) 2019 Elsevier B.V. All rights reserved.